Studies participating in GECCO are a rich resource, allowing for a large number of colorectal cancer (CRC) cases and controls to have well-harmonized clinical and environmental data. The harmonized data within GECCO allow investigators to examine gene-environment (GxE) interactions, focusing on known key epidemiologic risk factors for CRC.

We completed data harmonization on 15 studies for 74 variables in 11 categories, allowing core variables to be combined across studies and large sample sizes to be utilized for analyses.

As part of this work, Li Hsu developed the “cocktail method” for testing GxE interactions (Hsu et al. Genetic Epidemiology 2012). The Genome-Wide GxE working group also utilizes a new method developed by James Gauderman called Gauderman’s Two-Degrees of freedom screening test (publication pending).

To undertake this key area of interest, the Genome-Wide GxE working group leads analyses and publication of findings. They aim to determine how genetic and environmental factors can contribute to risk of developing colorectal cancer, to identify findings that will illuminate biological pathways and CRC etiology, and to translate findings to be applicable in the public health realm.

A summary of associations between key harmonized exposures and CRC risk.